21074565 has 32 divisors (see below), whose sum is σ = 34836480. Its totient is φ = 10873664.

The previous prime is 21074527. The next prime is 21074569. The reversal of 21074565 is 56547012.

It is a cyclic number.

It is not a de Polignac number, because 21074565 - 2¹¹ = 21072517 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21074569) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 117646 + ... + 117824.

It is an arithmetic number, because the mean of its divisors is an integer number (1088640).

Almost surely, 2^21074565 is an apocalyptic number.

It is an amenable number.

21074565 is a deficient number, since it is larger than the sum of its proper divisors (13761915).

21074565 is a wasteful number, since it uses less digits than its factorization.

21074565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 401.

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 21074565 is about 4590.7041943475. The cubic root of 21074565 is about 276.2185703001.

The spelling of 21074565 in words is "twenty-one million, seventy-four thousand, five hundred sixty-five".